Archive
New data on Tremadoc graptolites from Yukon, Canada
The Tremadocian subzones of Staurograptus tenuis. Anisograptus richardsoni. Clonograptus aureus, and Adelagraptus anriquus are given full zonal status in northern Richardson Mountains. Bryograptus ramosus Broggor and a species of Dictyonema are described from the upper Tremadotc. The occurrence of B. ramosus in the C. aureus Zone supports a correlation with shales of 3a(beta symbol) age in Norway.
Terebratulide affinity of the brachiopod Spirifera minima Moore
Investigation of seventy-three recently rediscovered specimens of Spiriferina? minima (Moore) enables resolution of the problem of possible synonymy with Nannirhynchia longirostra Baker, 1971. Comparison of the cardinal areas and delthyria of the two species enables the distinction between S.? minima and N. longirostra to be clearly demonstrated. Further, the characters of the shell show that S.? minima (Moore) is a juvenile terebratulidine assignable to Terebratula and that N. longirostra Baker is validly designated.
The lectotype of the ammonite Cadomites psilacanthus (Wermbter)
The inflated 'Am. humphriesianus' d'Orbigny (1845, pl. 134, figs. 1-4), non J. Sowerby (1825), has subsequently been named three times; the oldest objective synonym is Stephanoceras psilacanthus Wermbter (1891). The lectotype has been found in the British Museum (Natural History) and is redescribed. It probably came from the boundary Humphriesianum-Subfurcatum Zones at Sully, near Bayeux, Normandy. Specimens from the Parkinsoni Zone described under Cadomites arkelli Sturani (1964), the youngest objective synonym, are C. psilacanthus sturanii subsp. nov.
The production of faunal lists by automatic methods
Computer programs have been developed in the Institute of Geological Sciences which, after eliminating any unwanted data from original determinations, generate correctly type-set and punctuated faunal lists. These are suitable for direct publication or for easy incorporation into accounts dealing with wider geological topics.
A revision of the Triassic to lowest Jurassic dinoflagellate Rhaetogonyaulax
A re-evaluation of the dinoflagellate cyst genus Rhaetogonyaulax shows it to have a complex tabulation of 4'-?6', 5a-?6a, 1av, 7', 7c, 7'', 1p, 1pv, 3s, 3''. The archaeopyle is shown to be developed by loss of the epitract anterior to the precingular plate areas. In consequence of recognition of the high degree of intraspecific variability, all specimens examined are attributed to the single species R. rhaetica; the former species R. chaloneri is recognized as an extreme in the morphological range and reduced to varietal status.